Does anyone know anything about these lens?
http://www.ebay.com/itm/B-F-CO-DARLOT-16-INCH-PETZVAL-PORTRAIT-LENS-147588-/380412565849?pt=LH_DefaultDomain_0&hash=item58925b1959
What do you guys think the coverage would be? How hard is it to find stops for these? Is this a very soft focus lens? Good for wet Plate?

Mark Sawyer

20-Feb-2012, 11:30

You can find information on Darlot lenses here: http://antiquecameras.net/1890lenscatalogue.html

It's not a soft-focus lens, unless assembled wrong. Original stops would be hard to find, but easy to make yourself.The center will be quite sharp, but the outside of the image circle will be soft, due as much to field curvature as aberrations. The largest size in the catalogue is 15 inch, which is probably what this is. Advertised as covering 11x14, and the manufacturers usually went by the reasonably sharp area, so on 8x10, it would be sharp throughout the image, but with a shallow depth of field wide open. It would be quite appropriate for wet plate, and I'd venture to say a long Petzval of this type will go for quite a bit.